The medical workers who use hypodermic syringes incur considerable possibility of receiving sticks or pricks from the hypodermic needles used in the course of their daily work. Workers who clean up the medical facilities also incur the possibility of such needle pricks. Communicable diseases such as hepatitis and AIDS can be transmitted by these needle pricks. The need is evident for a hypodermic syringe which is disposable and which is readily disabled against the possibility of needle pricks and also against re-use.
The hypodermic syringe of the present invention requires few component parts, including a removable protective cap, and each of the parts may be mass produced at relatively little expense.
The syringe of the present invention may be filled with liquid for injection into a subject in the same manner as the prior art syringes. After use, the syringe plunger may be retracted and the hypodermic needle released for retraction into the syringe chamber by holding the syringe barrel with one hand and the syringe holding flange with the other hand, then twisting or rotating the syringe flange with respect to the barrel member. The needle is released into the syringe reservoir by the torsion and is permanently contained within the reservoir. The syringe needle is disabled against accidental sticking.
The presently known prior art are U. S. Pat. Nos. 3,584,626; 4,542,749; 4,710,170; 4,747,830; 4,747,831; 4,767,413; 4,770,655; 4,790,822; and 4,795,432.